It is known to feed a heating system from a heat pump, whereby the heat pump takes up heat from the surroundings. In small capacity plants it is common to drive the heat pump with an electric motor; but if the available quantity of heat from the surroundings is so great that it is sufficient at least partly to feed a municipal heating network, economical operation can be achieved according to the invention by driving the heat pump with its own combustion engine. This results in a favorable heat economy for the assembled unit, the capacity of which is determined by the amount of heat available in the surrounding.
An object of the invention is to provide a high capacity heat pump unit suitable for use in heating large buildings or municipalities.
Another object of the invention is to provide such a unit which is driven by a combustion engine and includes provision for scavenging heat from the engine exhaust.